Kenya has crossed a significant threshold with 21 million people now registered under the Social Health Authority (SHA), according to the 2026 Kenya Economic Survey. But beneath that milestone, county-level data reveals deep geographic inequality, with pockets of the country still largely outside the formal health insurance net. 

Women outnumber men on the national register, though a notable share of registrations carry no gender classification at all. A significant portion of memberships also lacks any county attachment, pointing to ongoing gaps in the scheme’s administrative infrastructure. 

Women account for 51.7 per cent of all registered members nationally, totalling 10.86 million against 9.93 million men at 47.3 per cent. A further 212,800 members, roughly one per cent, are recorded as unspecified in gender. Notably, 4.39 million of the 21 million registrations carry no county attachment, pointing to ongoing gaps in the scheme’s administrative infrastructure. 

Nairobi County leads by a wide margin with 1.64 million registered members, the only county to surpass one million. Its dominance reflects population density, formal employment concentration, and payroll-based SHA deductions across a vast civil service and corporate workforce. Female registrations in Nairobi alone reach 844,900, a figure higher than the total membership of most other counties. 

Kiambu follows with 832,300 members, buoyed by its proximity to Nairobi and the spillover of formal-sector employment into the capital’s commuter belt. Nakuru (730,300), Mombasa (704,400), and Kakamega (700,000) round out the top five. 

Bottom counties are largely arid or semi-arid, sparsely populated, underserved in formal employment and public service delivery 

At the other end, Isiolo sits at the very bottom with just 47,000 registered members, followed by Lamu (66,500), Tana River (68,600), Samburu (69,000), and Marsabit (90,800). These five counties share a common profile: largely arid or semi-arid, sparsely populated, and historically underserved in formal employment and public service delivery. 

The combined membership of the bottom ten counties, which also includes West Pokot (112,700), Taita/Taveta (151,900), Garissa (159,100), Turkana (167,000), and Tharaka-Nithi (178,000), totals just 1.11 million across ten counties. That is an average of 111,100 per county, less than a third of the national county average of 353,400. 

The top ten counties, led by Nairobi, collectively register 7.19 million members, just over a third of the national figure. The female share within this group reaches 52.8 per cent, slightly above the national figure, suggesting women in high-registration counties are disproportionately captured in the system relative to their male counterparts. 

Interestingly, the female share within the bottom ten counties is actually slightly higher at 53.0 per cent. This likely reflects women’s greater engagement with maternal and child health services, which are often the most common touchpoints for SHA enrolment in rural areas. 

Low unspecified-gender counts in Mandera, Wajir and Garissa suggest a possible undercounting of women 

Regional patterns add further texture. The Nyanza region is notably well-represented, with Kisumu, Homa Bay, Kisii, Siaya, Migori, and Nyamira all appearing in the middle-to-upper range. Homa Bay’s female membership of 259,700 against a male count of 214,500 represents one of the more pronounced gender gaps in the dataset, likely tied to the region’s historically higher rates of female-headed households. 

The Rift Valley presents the widest internal spread, with Nakuru ranking third nationally while Samburu sits near the bottom. North Eastern is the most consistently underperforming region, with Mandera (216,300), Wajir (182,900), and Garissa (159,100) all ranking in the lower half. Low unspecified-gender counts there suggest a possible undercounting of women in contexts where female health-seeking behaviour may be constrained by cultural or geographic barriers. 

On data quality, Murang’a records only two unspecified-gender registrations, the lowest of any county, likely reflecting tighter administrative processing rather than demographic homogeneity. By contrast, Kakamega logs 18,400 unspecified members and Kisumu 16,100, suggesting that registration drive volume may sometimes outpace data quality. Lamu is a particular outlier: 4,400 of its 66,500 registrations carry no gender classification, roughly 6.6 per cent, the highest proportion in the country. 

Sources: Kenya Economic Survey 2026, SHA, KNBS.

Data analytics & visualisation: Stanley Njihia 

Text: Yvonne Kawira