OBJECTIVES: Many obligate cost-utility Health Technology Assessment (HTA) bodies formally or informally reference incremental cost-effectiveness ratio (ICER) thresholds as key criteria that new medicines must satisfy to receive reimbursement approval. One such body, the National Institute of Health and Care Excellence (NICE), in 2004 defined its ICER threshold at £20,000 per quality added life year (QALY), rising to a maximum of £30,000/QALY if specific exceptional circumstances applied. Nevertheless, this basic threshold range has remained unaltered and has not accounted for inflation, the rate at which the general level of prices for goods and services rises. This research aims to model how the NICE threshold would vary if it fluctuated in line with the UK inflation rate and what effect this could have on appraisal outcomes. METHODS: Annual UK historical and forecast inflation rates were sourced from rateinflation.com (2004- 2016), upon which the effects on the NICE thresholds were modelled. Base-case ICERs were extracted from NICE Single Technology Appraisal (STA) reports for oncologics from 2006-July 2014. RESULTS: Annual UK inflation rates varied from 0.4% to 4.5% (average 2.4%). Cumulatively, this amounts to a 29% decrease in the value of UK currency in this period. This means that in 2016 the NICE thresholds would need to rise to £26,100 and £39,150 to be monetarily equivalent to their 2004 levels.  60 NICE STA reports with base-case ICERs were extracted (average $68,636/QALY, range: US$5,390-234,009/QALY), 27 of which (45%) were not recommended. 35% (23/65) had a base-case ICER below £30,000 but this increased to 52% (34/65) if the £39,150 threshold is utilised. CONCLUSIONS: The cumulative effects of inflation over time can be substantial. HTA bodies are artificially raising this threshold by not accounting for this fall in the currency purchasing power over time. ICER thresholds should be subject to periodic updating to account for inflation.