⚠ Part D and Supplement Are Drifting DownLow threat

UnitedHealth Group (UNH) — threat to the moat

UnitedHealthcare's stand-alone Part D membership fell 18% in two and a half years, a slow retreat from a product linked to its own pharmacy business.

Beyond Medicare Advantage, UnitedHealthcare's other senior products are shrinking slowly. Stand-alone Part D drug plan membership was 3,315,000 at the end of 2023 and 2,710,000 in June 202612, a fall of about 18%3. Medicare Supplement membership went from 4,355,000 to 4,260,000 over the same period45.

Senior product members (thousands)3,315Part D Dec 20232,710Part D Jun 20264,355Supplement Dec 20234,260Supplement Jun 2026UnitedHealth Group Form 10-K FY2025; Q2 2026 results release
Slow declines in both.

These products matter because they are a way to reach seniors who do not choose Medicare Advantage, and because they carry different risks. A shrinking stand-alone drug book reduces UnitedHealthcare's presence in the part of Medicare where Optum Rx also earns money.

The declines are small next to the company's size. Total UnitedHealthcare medical membership was 48,525,000 in June 20266.

The products are still large in absolute terms. UnitedHealthcare enrolled 10.4 million people in Medicare Part D programmes in total, including those in Medicare Advantage plans with drug coverage7. The stand-alone book is the part that sells to seniors who keep traditional Medicare, and it fell by 30,000 between March and June 2026 alone89.

The trend to follow is stand-alone Part D membership. A fall below 2.5 million would say the company is conceding that market rather than repricing it.

References
  1. ReportedStand-alone Part D drug plan membership was 3,315,000 at the end of 2023 and 2,710,000 in June 2026, a fall of about 18%.
    UnitedHealth Group Form 10-K for fiscal 2025 - Item 7 MD&A: consolidated and segment results, medical care ratio, membership and operating metrics. — FY2025 · publ. 2 March 2026 · source ↗
  2. ReportedStand-alone Part D drug plan membership was 3,315,000 at the end of 2023 and 2,710,000 in June 2026, a fall of about 18%.
    UnitedHealth Group second-quarter 2026 results release, Form 8-K exhibit 99.1 - segment results, operating metrics and people served. — Q2 2026 · publ. 16 July 2026 · source ↗
  3. Moat Explorer calcStand-alone Part D drug plan membership was 3,315,000 at the end of 2023 and 2,710,000 in June 2026, a fall of about 18%.
    Moat Explorer calculation from UnitedHealth Group's reported figures ($ millions unless stated). External revenue by segment = segment revenue less affiliated revenue (10-K segment notes): 2021 UnitedHealthcare 222,899; Optum Health 54,065 - 29,234 = 24,831; Optum Insight 12,199 - 7,867 = 4,332; Optum Rx 91,314 - 55,779 = 35,535; total 287,597. 2022: 249,741; 71,174 - 40,883 = 30,291; 14,581 - 9,288 = 5,293; 99,773 - 60,936 = 38,837; total 324,162. 2023: 281,360; 95,319 - 57,696 = 37,623; 18,932 - 10,896 = 8,036; 116,087 - 71,484 = 44,603; total 371,622. 2024: 298,208; 105,358 - 63,883 = 41,475; 18,757 - 11,881 = 6,876; 133,231 - 79,512 = 53,719; total 400,278. 2025: 344,903; 101,957 - 63,615 = 38,342; 19,417 - 12,948 = 6,469; 154,726 - 96,873 = 57,853; total 447,567. Q2 2026 (2026 basis): 86,017; 23,472 - 14,353 = 9,119; 5,402 - 3,556 = 1,846; 38,292 - 23,242 = 15,050; total 112,032; Optum external 9,119 + 1,846 + 15,050 = 26,015. Optum external revenue = Optum revenue less corporate eliminations: 155,565 - 90,867 = 64,698 (2021); 182,768 - 108,347 = 74,421 (2022); 226,635 - 136,373 = 90,262 (2023); 252,957 - 150,887 = 102,070 (2024); 270,620 - 167,956 = 102,664 (2025); 102,664 / 102,070 - 1 = 0.6%. Optum revenue from inside the group: 90,867 / 155,565 = 58.4%; 108,347 / 182,768 = 59.3%; 136,373 / 226,635 = 60.2%; 150,887 / 252,957 = 59.6%; 167,956 / 270,620 = 62.1%; Q2 2026 39,648 / 65,663 = 60.4%. Affiliated shares 2025: Optum Health 63,615 / 101,957 = 62%; Optum Insight 12,948 / 19,417 = 67%; Optum Rx 96,873 / 154,726 = 63%. Affiliated revenue as share of UnitedHealthcare revenue 167,956 / 344,903 = 49%. Segment shares of consolidated revenue 2025: UnitedHealthcare 344,903 / 447,567 = 77%; Optum Rx 57,853 / 447,567 = 12.9%; Optum Health 38,342 / 447,567 = 8.6%; Optum Insight 6,469 / 447,567 = 1.4%. Q2 2026 UnitedHealthcare 86,017 / 112,032 = 76.8%. Compound growth 2021-2025: UnitedHealthcare (344,903 / 222,899)^(1/4) - 1 = 11.5%; Optum Rx external (57,853 / 35,535)^(1/4) - 1 = 13.0%. Segment margins: UnitedHealthcare 11,975 / 222,899 = 5.4% (2021), 14,379 / 249,741 = 5.8% (2022); Optum Rx 4,135 / 91,314 = 4.5% (2021), 4,436 / 99,773 = 4.4% (2022); Optum Insight 3,398 / 12,199 = 27.9% (2021), 3,588 / 14,581 = 24.6% (2022); Optum Health H1 2026 2,331 / 47,581 = 4.9%. Optum earnings decline 16,703 - 9,539 = 7,164, 7,164 / 16,703 = 42.9%. Optum Health H1 2026 revenue 47,581 / 49,562 - 1 = -4.0%; earnings 2,331 / 1,840 - 1 = +26.7%; affiliated revenue Q2 14,353 / 15,845 - 1 = -9.4%. Optum Health 2025 recast margin -1,115 / 100,051 = -1.1%; 2024 6,902 / 103,516 = 6.7%. Medical care ratio 2015-2019 from EDGAR XBRL medical costs / premiums: 103,875 / 127,163 = 81.7%; 117,038 / 144,118 = 81.2%; 130,036 / 158,453 = 82.1%; 145,403 / 178,087 = 81.6%; 156,440 / 189,699 = 82.5%. Premiums 127,163 (2015) and 257,157 (2022). Operating earnings 11,021 (2015, XBRL). One point of medical care ratio on 2025 premiums: 352,229 x 1% = 3,522; 3,522 / 18,964 = 18.6% of operating earnings. Q2 2026 favorable development 860 / 86,956 premiums = 1.0 point. Membership: commercial risk-based 8,845 - 7,655 = 1,190 thousand, 1,190 / 8,845 = 13.5%; Medicare Advantage 8,445 - 7,565 = 880 thousand, 880 / 8,445 = 10.4%; Medicaid 7,845 - 6,780 = 1,065 thousand, 1,065 / 7,845 = 13.6%; Part D stand-alone (3,315 - 2,710) / 3,315 = 18.3%. Community & State revenue per year-end Medicaid member 75,004 / 7.845 = 9,561 dollars (2023); 94,390 / 7.380 = 12,790 dollars (2025). Optum Rx quarterly scripts (414 - 387) / 414 = 6.5%. Optum Insight backlog: external 32.8 - 12.5 = 20.3 bn (2024), 31.1 - 12.9 = 18.2 bn (2025), change -10.3%; affiliated share 12.5 / 32.8 = 38%, 12.9 / 31.1 = 41%. Cyberattack provider loans 9,033 - 4,514 - 1,680 = 2,839 not yet repaid at end-2025. Market value against peers: 108.78 + 86.37 + 70.16 + 45.67 + 30.59 + 10.07 = 351.64 bn; 338.03 / 351.64 = 96%. CMS premium revenue 44% x 447,567 = 196,929 (about 197 bn); all other 447,567 - 196,929 = 250,638. Medicare & Retirement share of UnitedHealthcare revenue Q2 2026: 42,390 / 86,017 = 49.3%. Premiums share of revenue Q2 2026: 86,956 / 112,032 = 77.6%. Capital returns 2025: dividends 7,916 + buybacks 5,545 = 13,461; 13,461 / 12,056 = 112% of net earnings; free cash flow 19,697 - 3,622 = 16,075; 13,461 / 16,075 = 84%. Goodwill 44,453 (2015, XBRL) and 110,499 (2025); goodwill plus other intangibles 110,499 + 20,474 = 130,973; 130,973 / 309,581 = 42.3% of assets. Long-term debt 25,331 (2015, XBRL). Interest expense / operating earnings: 3,246 / 32,358 = 10.0% (2023); 4,002 / 18,964 = 21.1% (2025). Rate sensitivity net 345 - 273 = 72. Investment income (3,920 - 5,202) / 5,202 = -24.6%; 4,089 / 371,622 = 1.1% of 2023 revenue. Net interest-bearing debt: 6,069 + 72,320 - 28,121 = 50,268 (Dec 2025); 3,827 + 69,501 - 31,468 = 41,860 (Jun 2026). 2025 guidance: original adjusted EPS midpoint (29.50 + 30.00) / 2 = 29.75; April (26.00 + 26.50) / 2 = 26.25; actual 16.35 / 29.75 - 1 = -45%. 2026 adjusted EPS midpoint (19.50 + 20.00) / 2 = 19.75. Progress vs 2026 guidance: operating earnings 16,981 / 25,450 = 66.7%. Q2 2026 operating earnings 7,991 / 5,150 - 1 = +55%. Gross segment revenue 2025: 344,903 + 101,957 + 19,417 + 154,726 = 621,003; less Optum eliminations 5,480 and corporate eliminations 167,956 = 447,567. Medical costs 313,995 / 264,185 - 1 = 18.9%; medical costs payable 39,337 / 34,224 - 1 = 14.9%. Commercial risk-based members 8,165 - 7,725 = 440 thousand (Q1 2026), 7,725 - 7,655 = 70 thousand (Q2 2026). Medicaid 7,380 - 6,780 = 600 thousand (six months to June 2026); 7,845 - 7,380 = 465 thousand (2023-2025). Optum Rx Q4 2025 share of year 2,885 / 7,193 = 40%. Goodwill 110,499 - 106,734 = 3,765. Total debt 6,069 + 72,320 = 78,389. Dividend at 9.28 x 897.6 million shares = 8,330, 8,330 / 16,750 = 50%. Year-end P/E 2015-2020: 19.3, 21.7, 20.2, 20.0, 20.1, 21.6 (market value / net earnings). H1 2026 medical care ratio 148,847 / 174,517 = 85.3%. Part D stand-alone 2,740 - 2,710 = 30 thousand (Q2 2026). Rounded external revenue ($bn): Optum Rx 35.5, 38.8, 44.6, 53.7, 57.9 (2021-2025), 15.1 (Q2 2026); Optum Health 24.8, 30.3, 37.6, 41.5, 38.3, 9.1 (Q2 2026); Optum Insight 4.3, 5.3, 8.0, 6.9, 6.5, 1.8 (Q2 2026); Optum 64.7, 74.4, 90.3, 102.1, 102.7; net debt 50.3 and 41.9; total debt 78.4; UnitedHealthcare revenue 222.9, 249.7, 281.4, 298.2, 344.9. Optum 2026 guidance 13,450 / 9,539 - 1 = +41%. Corporate eliminations Q2 39,648 / 41,712 - 1 = -4.9%. Net interest-bearing debt / total equity 50,268 / 100,090 = 0.50. Valuation: 2026 net margin implied by guidance 16,750 / 439,000 = 3.8%; 2023 net margin 6.0% x 439.0 bn = 26.3 bn; 338.03 / 26.34 = 12.8 times - ratios, growth rates and membership changes. — 2015-2026 · publ. September 2026 · source ↗
    Method: Arithmetic on figures reported in UnitedHealth Group's Forms 10-K and 10-Q, results releases, SEC EDGAR XBRL and market data; operands shown in the source line.
  4. ReportedMedicare Supplement membership went from 4,355,000 to 4,260,000 over the same period.
    UnitedHealth Group Form 10-K for fiscal 2025 - Item 7 MD&A: consolidated and segment results, medical care ratio, membership and operating metrics. — FY2025 · publ. 2 March 2026 · source ↗
  5. ReportedMedicare Supplement membership went from 4,355,000 to 4,260,000 over the same period.
    UnitedHealth Group second-quarter 2026 results release, Form 8-K exhibit 99.1 - segment results, operating metrics and people served. — Q2 2026 · publ. 16 July 2026 · source ↗
  6. ReportedTotal UnitedHealthcare medical membership was 48,525,000 in June 2026.
    UnitedHealth Group second-quarter 2026 results release, Form 8-K exhibit 99.1 - segment results, operating metrics and people served. — Q2 2026 · publ. 16 July 2026 · source ↗
  7. ReportedUnitedHealthcare enrolled 10.4 million people in Medicare Part D programmes in total, including those in Medicare Advantage plans with drug coverage.
    UnitedHealth Group Form 10-K for fiscal 2025 - Item 1 business: segments, products, people served and leadership. — FY2025 · publ. 2 March 2026 · source ↗
  8. ReportedThe stand-alone book is the part that sells to seniors who keep traditional Medicare, and it fell by 30,000 between March and June 2026 alone.
    UnitedHealth Group second-quarter 2026 results release, Form 8-K exhibit 99.1 - segment results, operating metrics and people served. — Q2 2026 · publ. 16 July 2026 · source ↗
  9. Moat Explorer calcThe stand-alone book is the part that sells to seniors who keep traditional Medicare, and it fell by 30,000 between March and June 2026 alone.
    Moat Explorer calculation from UnitedHealth Group's reported figures ($ millions unless stated). External revenue by segment = segment revenue less affiliated revenue (10-K segment notes): 2021 UnitedHealthcare 222,899; Optum Health 54,065 - 29,234 = 24,831; Optum Insight 12,199 - 7,867 = 4,332; Optum Rx 91,314 - 55,779 = 35,535; total 287,597. 2022: 249,741; 71,174 - 40,883 = 30,291; 14,581 - 9,288 = 5,293; 99,773 - 60,936 = 38,837; total 324,162. 2023: 281,360; 95,319 - 57,696 = 37,623; 18,932 - 10,896 = 8,036; 116,087 - 71,484 = 44,603; total 371,622. 2024: 298,208; 105,358 - 63,883 = 41,475; 18,757 - 11,881 = 6,876; 133,231 - 79,512 = 53,719; total 400,278. 2025: 344,903; 101,957 - 63,615 = 38,342; 19,417 - 12,948 = 6,469; 154,726 - 96,873 = 57,853; total 447,567. Q2 2026 (2026 basis): 86,017; 23,472 - 14,353 = 9,119; 5,402 - 3,556 = 1,846; 38,292 - 23,242 = 15,050; total 112,032; Optum external 9,119 + 1,846 + 15,050 = 26,015. Optum external revenue = Optum revenue less corporate eliminations: 155,565 - 90,867 = 64,698 (2021); 182,768 - 108,347 = 74,421 (2022); 226,635 - 136,373 = 90,262 (2023); 252,957 - 150,887 = 102,070 (2024); 270,620 - 167,956 = 102,664 (2025); 102,664 / 102,070 - 1 = 0.6%. Optum revenue from inside the group: 90,867 / 155,565 = 58.4%; 108,347 / 182,768 = 59.3%; 136,373 / 226,635 = 60.2%; 150,887 / 252,957 = 59.6%; 167,956 / 270,620 = 62.1%; Q2 2026 39,648 / 65,663 = 60.4%. Affiliated shares 2025: Optum Health 63,615 / 101,957 = 62%; Optum Insight 12,948 / 19,417 = 67%; Optum Rx 96,873 / 154,726 = 63%. Affiliated revenue as share of UnitedHealthcare revenue 167,956 / 344,903 = 49%. Segment shares of consolidated revenue 2025: UnitedHealthcare 344,903 / 447,567 = 77%; Optum Rx 57,853 / 447,567 = 12.9%; Optum Health 38,342 / 447,567 = 8.6%; Optum Insight 6,469 / 447,567 = 1.4%. Q2 2026 UnitedHealthcare 86,017 / 112,032 = 76.8%. Compound growth 2021-2025: UnitedHealthcare (344,903 / 222,899)^(1/4) - 1 = 11.5%; Optum Rx external (57,853 / 35,535)^(1/4) - 1 = 13.0%. Segment margins: UnitedHealthcare 11,975 / 222,899 = 5.4% (2021), 14,379 / 249,741 = 5.8% (2022); Optum Rx 4,135 / 91,314 = 4.5% (2021), 4,436 / 99,773 = 4.4% (2022); Optum Insight 3,398 / 12,199 = 27.9% (2021), 3,588 / 14,581 = 24.6% (2022); Optum Health H1 2026 2,331 / 47,581 = 4.9%. Optum earnings decline 16,703 - 9,539 = 7,164, 7,164 / 16,703 = 42.9%. Optum Health H1 2026 revenue 47,581 / 49,562 - 1 = -4.0%; earnings 2,331 / 1,840 - 1 = +26.7%; affiliated revenue Q2 14,353 / 15,845 - 1 = -9.4%. Optum Health 2025 recast margin -1,115 / 100,051 = -1.1%; 2024 6,902 / 103,516 = 6.7%. Medical care ratio 2015-2019 from EDGAR XBRL medical costs / premiums: 103,875 / 127,163 = 81.7%; 117,038 / 144,118 = 81.2%; 130,036 / 158,453 = 82.1%; 145,403 / 178,087 = 81.6%; 156,440 / 189,699 = 82.5%. Premiums 127,163 (2015) and 257,157 (2022). Operating earnings 11,021 (2015, XBRL). One point of medical care ratio on 2025 premiums: 352,229 x 1% = 3,522; 3,522 / 18,964 = 18.6% of operating earnings. Q2 2026 favorable development 860 / 86,956 premiums = 1.0 point. Membership: commercial risk-based 8,845 - 7,655 = 1,190 thousand, 1,190 / 8,845 = 13.5%; Medicare Advantage 8,445 - 7,565 = 880 thousand, 880 / 8,445 = 10.4%; Medicaid 7,845 - 6,780 = 1,065 thousand, 1,065 / 7,845 = 13.6%; Part D stand-alone (3,315 - 2,710) / 3,315 = 18.3%. Community & State revenue per year-end Medicaid member 75,004 / 7.845 = 9,561 dollars (2023); 94,390 / 7.380 = 12,790 dollars (2025). Optum Rx quarterly scripts (414 - 387) / 414 = 6.5%. Optum Insight backlog: external 32.8 - 12.5 = 20.3 bn (2024), 31.1 - 12.9 = 18.2 bn (2025), change -10.3%; affiliated share 12.5 / 32.8 = 38%, 12.9 / 31.1 = 41%. Cyberattack provider loans 9,033 - 4,514 - 1,680 = 2,839 not yet repaid at end-2025. Market value against peers: 108.78 + 86.37 + 70.16 + 45.67 + 30.59 + 10.07 = 351.64 bn; 338.03 / 351.64 = 96%. CMS premium revenue 44% x 447,567 = 196,929 (about 197 bn); all other 447,567 - 196,929 = 250,638. Medicare & Retirement share of UnitedHealthcare revenue Q2 2026: 42,390 / 86,017 = 49.3%. Premiums share of revenue Q2 2026: 86,956 / 112,032 = 77.6%. Capital returns 2025: dividends 7,916 + buybacks 5,545 = 13,461; 13,461 / 12,056 = 112% of net earnings; free cash flow 19,697 - 3,622 = 16,075; 13,461 / 16,075 = 84%. Goodwill 44,453 (2015, XBRL) and 110,499 (2025); goodwill plus other intangibles 110,499 + 20,474 = 130,973; 130,973 / 309,581 = 42.3% of assets. Long-term debt 25,331 (2015, XBRL). Interest expense / operating earnings: 3,246 / 32,358 = 10.0% (2023); 4,002 / 18,964 = 21.1% (2025). Rate sensitivity net 345 - 273 = 72. Investment income (3,920 - 5,202) / 5,202 = -24.6%; 4,089 / 371,622 = 1.1% of 2023 revenue. Net interest-bearing debt: 6,069 + 72,320 - 28,121 = 50,268 (Dec 2025); 3,827 + 69,501 - 31,468 = 41,860 (Jun 2026). 2025 guidance: original adjusted EPS midpoint (29.50 + 30.00) / 2 = 29.75; April (26.00 + 26.50) / 2 = 26.25; actual 16.35 / 29.75 - 1 = -45%. 2026 adjusted EPS midpoint (19.50 + 20.00) / 2 = 19.75. Progress vs 2026 guidance: operating earnings 16,981 / 25,450 = 66.7%. Q2 2026 operating earnings 7,991 / 5,150 - 1 = +55%. Gross segment revenue 2025: 344,903 + 101,957 + 19,417 + 154,726 = 621,003; less Optum eliminations 5,480 and corporate eliminations 167,956 = 447,567. Medical costs 313,995 / 264,185 - 1 = 18.9%; medical costs payable 39,337 / 34,224 - 1 = 14.9%. Commercial risk-based members 8,165 - 7,725 = 440 thousand (Q1 2026), 7,725 - 7,655 = 70 thousand (Q2 2026). Medicaid 7,380 - 6,780 = 600 thousand (six months to June 2026); 7,845 - 7,380 = 465 thousand (2023-2025). Optum Rx Q4 2025 share of year 2,885 / 7,193 = 40%. Goodwill 110,499 - 106,734 = 3,765. Total debt 6,069 + 72,320 = 78,389. Dividend at 9.28 x 897.6 million shares = 8,330, 8,330 / 16,750 = 50%. Year-end P/E 2015-2020: 19.3, 21.7, 20.2, 20.0, 20.1, 21.6 (market value / net earnings). H1 2026 medical care ratio 148,847 / 174,517 = 85.3%. Part D stand-alone 2,740 - 2,710 = 30 thousand (Q2 2026). Rounded external revenue ($bn): Optum Rx 35.5, 38.8, 44.6, 53.7, 57.9 (2021-2025), 15.1 (Q2 2026); Optum Health 24.8, 30.3, 37.6, 41.5, 38.3, 9.1 (Q2 2026); Optum Insight 4.3, 5.3, 8.0, 6.9, 6.5, 1.8 (Q2 2026); Optum 64.7, 74.4, 90.3, 102.1, 102.7; net debt 50.3 and 41.9; total debt 78.4; UnitedHealthcare revenue 222.9, 249.7, 281.4, 298.2, 344.9. Optum 2026 guidance 13,450 / 9,539 - 1 = +41%. Corporate eliminations Q2 39,648 / 41,712 - 1 = -4.9%. Net interest-bearing debt / total equity 50,268 / 100,090 = 0.50. Valuation: 2026 net margin implied by guidance 16,750 / 439,000 = 3.8%; 2023 net margin 6.0% x 439.0 bn = 26.3 bn; 338.03 / 26.34 = 12.8 times - ratios, growth rates and membership changes. — 2015-2026 · publ. September 2026 · source ↗
    Method: Arithmetic on figures reported in UnitedHealth Group's Forms 10-K and 10-Q, results releases, SEC EDGAR XBRL and market data; operands shown in the source line.
Sources
Generated September 26, 2026